1. Field of the Invention
The present invention relates to a composition for solidifying soil and industrial waste, and more particularly to a composition for solidifying soil and industrial waste, which contains straight asphalt as a main component and can be added to a single kind of or a mixture of soil, such as decomposed granite soil, mud, river sand and sea sand, a single kind of industrial waste or a mixture of industrial waste, such as slag, powder slag, waste concrete and sludge, and a small amount of cement, to form solidified materials which can be used as substitutes for stone materials.
2. Description of the Prior Art
These days, due to the difficulty in securing good-quality construction materials for public works and construction industries, the construction period is lengthened, which increases expenses. Also, to secure construction materials, stony mountains are exploited or aggregate is extracted from rivers, sea floors and the like, thus destroying the natural environment and disturbing ecosystems. Specifically, because granular materials such as stone materials are used in harbor landfill and asphalt and concrete paving, fields and mountains are destroyed to quarry stones, and stone cutting, transport and breaking works act as factors that increase construction expenses. In addition, because general soil is used in most riverbank construction, dikes break due to the reduction in durability and safety caused by scouring resulting from water stream pressure, resulting in flood damage and the spread of disease. Also, in the case of soft ground improvement according to the prior art, a high construction cost is incurred and the loss of the material used is high.
To solve these problems, there have been attempts to recycle soil and industrial waste, widely available in Korea, as a substitute for stone materials in various public works and other construction industries.
In such attempts, cement stabilization methods, LAC (lignin rosin asphalt concrete) methods and the like have been developed and used. However, materials according to these methods have a long curing time, making it difficult to obtain early compressive strength, and also have a low compressive strength of 100 kgf/cm2. For this reason, the application of these materials has been limited to sub-base layer materials in road construction and the like.
In another attempt, Korean Patent Laid-Open Publication No. 1996-29280 discloses a method for curing a mixture of industrial waste and soil using a curing agent composition. In this method, the curing agent composition comprises 25% sodium carbonate, 25% potassium chloride, 15% magnesium carbonate, 10% ammonium chloride, 8% potassium silicate, 7% silicate, 5% ferrous sulfate and 5% titanium oxide. The curing agent is described as being suitable for solidifying a mixture of industrial waste and soil, but it contains sodium carbonate and potassium chloride as main components, and thus it is expensive. Also, the strength of solidified materials prepared using the curing agent is not greatly increased, and thus there is a need to develop a solidifying agent which can further increase the strength of solidified materials.
As described above, stone materials can be used in a wide range of applications, including harbors, seashores, roads, airports, water resource development, soil and public works, but the resources thereof are restricted. For this reason, there has been an urgent demand for a method of making it possible to recycle industrial waste, which is generated in construction fields in large amounts and is readily available, and soil, such as decomposed granite soil.
According to this demand, the present inventors filed a patent application relating to a solidifying composition containing 25-35 wt % of emulsified asphalt, 0.05-0.20 wt % of an emulsifier for asphalt, 0.1-0.3 wt % of hydrochloric acid, 0.01-0.05 wt % of calcium chloride, 0.1-0.5 wt % of lignin, 0.01-0.05 wt % of oleic acid, 0.005-0.030 wt % of a surfactant, and the balance of water (Korean Patent Application No. 2005-0070705, filed on Aug. 2, 2005). However, this composition has problems in that it contains emulsified asphalt, which increases the production cost of the composition, and it shows insufficient impact resistance or low flexibility.